Generally, people use voice calls/data connection to a major extent as a way of communicating with other people. People rely on different kinds of User Equipment (UE) to establish connection for voice calls/data connection using different network operators. The generated voice calls/data connection may be between. UE's belonging to different network operators or UE's belonging to same network operators.
Existing techniques establish connection for voice calls/data connection, by initially sending a request from the UE for initialising voice calls/data connection to Evolved Node B (eNodeB). Evolved Node B (eNodeB) is a hardware that is connected to the mobile phone network that communicates directly with mobile handsets (UEs) like a Base Transceiver Station (BTS) in GSM networks. The eNodeB then forwards the request to a Mobility Management Entity (MME). The MME is a key component of the standards-defined Evolved Packet Core (EPC) for Long Term Evolution (LTE) network. The MME may provide mobility session management for the LTE network and supports subscriber authentication, roaming and handovers to other networks. Thereafter, the MME forwards the request to Serving Gateway/Packet data network Gateway (SGW/PGW) for setting up a connection between the eNodeB and SGW/PGW. The method of establishing connection for voice calls/data connection between two UEs is same irrespective of whether the UEs belong to the same network operator or different network operators. Therefore, anchoring the connection at the SGW/PGW for UEs belonging to same network as well as different networks causes high traffic on MME/SGW/PGW. The high traffic leads to delay in establishing connections or sometimes leads to congestion at the MME/SGW/PGW.
In the existing techniques, for establishing voice calls/data connection, the UE has to fall back to second-generation (2G). The main reason for the fall back is that LTE network does not have any procedure to setup connection of the voice calls/data connection over LTE network without assigning Internet Protocol (IP) address to the UE. The LTE network is designed based on IP network architecture which may not allow operator to setup a connection for voice calls/data connection between two UEs without assigning IP address. Further, this IP address is a private IP address known only to the MME and not to each UE in order to communicate directly without any help of the IP Multimedia Subsystem (IMS) or PGW. Therefore we need a mechanism for two UEs to communicate directly without CS-fallback.